count the frequency of letters in given word

Question

I need help on writing a program about counting how many times a letter in a given word is repeated in alphabetical order. Lower and upper case letters are equals and it has to work for numbers as well. For example:

we have to use array and loops. also, it must not count the space if there is more than 1 word /number given and it should also prompt the user if they want to continue or not. If not then they should enter a dot '.' or when there's a dot '.' after the word, it should close the program after counting the letters.

University
e:1 i:2 n:1 r:1 s:1 t:1 u:1 y:1

import java.util.Scanner;
import java.lang.Character;
public class Array {

    public static void main(String[] args) {
        Scanner input=new Scanner (System.in);
        int[] letters =new int [26];
        String str= input.nextLine();
        str=str.toLowerCase();

        for (int i=0; i<str.length(); i++)
        {
            letters[i]=0;
        }
        System.out.println(str.length());
        System.out.println(char2int('a'));
        System.out.println(char2int ('D'));
    }

    public static int char2int (char c) {
        return Character.toLowerCase(c)-(int)'a';
    }
}

This comes out to, for example
me
2
0
3

Answer 1

I'm going to give you a big hint, what you need to do is call a method (say countLetters ) that takes a word and a letter - so that would be,

// Count the "letter"(s) in the word.
public static int countLetters(String word, char letter) {
  int count = 0;
  if (word != null) {
    char lc = Character.toLowerCase(letter);
    for (char c : word.toCharArray()) {
      if (lc == Character.toLowerCase(c)) {
        count++;
      }
    }
  }
  System.out.printf("%s: %d\n",
      String.valueOf(letter), count);
  return count;
}

public static void main(String[] args) {
  String test = "Universe";
  countLetters(test, 'e');
  countLetters(test, 'u');
}

Output is

e: 2
u: 1